Necrotizing Mucormycosis of Wounds Following Combat Injuries, Natural Disasters, Burns, and Other Trauma

Necrotizing mucormycosis is a devastating complication of wounds incurred in the setting of military (combat) injuries, natural disasters, burns, or other civilian trauma. Apophysomyces species, Saksenaea species and Lichtheimia (formerly Absidia) species, although uncommon as causes of sinopulmonary mucormycosis, are relatively frequent agents of trauma-related mucormycosis. The pathogenesis of these infections likely involves a complex interaction among organism, impaired innate host defenses, and biofilms related to traumatically implanted foreign materials. Effective management depends upon timely diagnosis, thorough surgical debridement, and early initiation of antifungal therapy.

Antifungal-resistant Mucorales in different indoor environments

This paper sought to address the prevalence of Mucorales in different indoor environments in Portugal. Environmental samples (183 in total) were collected at dwellings (n = 79) and workplaces (bakeries, swine farms, taxis, waste-sorting plants) (n = 93) by passive sampling using electrostatic dust collector (EDC), air-conditioning filters, litter, and/or raw materials. Samples were inoculated onto non-selective MEA and DG18 media and were screened for antifungal drug-resistance in azole-supplemented agar Sabouraud media. A probe-based Mucorales-specific real-time PCR assay (Muc18S) was used to detect Mucorales in complement to conventional culture-based methods. Mucorales order was found as more prevalent in air-conditioning filters from waste-sorting fork lifters (35.7%). Amongst Mucorales isolates able to grow in azole-supplemented media, 16 isolates of Mucor sp., Rhizopus sp. or Rhizomucor sp. were not susceptible to 1 mg/L voriconazole, and four isolates of Mucor sp. or Rhizopus sp. were not susceptible to 4 mg/L itraconazole. In conclusion, combination of the culture-based and molecular methods proved to be reliable for Mucorales order identification in complex environmental samples.

Emerging fungal infections in solid organ transplant recipients: Guidelines of the American Society of Transplantation Infectious Diseases Community of Practice

These updated AST-IDCOP guidelines review the epidemiology, diagnosis, and management of emerging fungi after organ transplantation. Infections due to numerous generally innocuous fungi are increasingly recognized in solid organ transplant (SOT) recipients, comprising about 7%-10% of fungal infections in this setting. Such infections are collectively referred to as emerging fungal infections and include Mucormycetes, Fusarium, Scedosporium, and dematiaceous fungi among others. The causative organisms are diverse in their pathophysiology, uncommon in the clinical setting, have evolving nomenclature, and are often resistant to multiple commonly used antifungal agents. In recent years significant advances have been made in understanding of the epidemiology of these emerging fungal infections, with improved diagnosis and expanded treatment options. Still, treatment guidelines are generally informed by and limited to experience from cohorts of patients with hematological malignancies and/or solid and stem cell transplants. While multicenter randomized controlled trials are not feasible for these uncommon infections in SOT recipients, collaborative prospective studies can be valuable in providing information on the epidemiology, clinical manifestations, treatment strategies, and outcomes associated with the more commonly encountered infections.

Galleria mellonella as a model system to study virulence potential of mucormycetes and evaluation of antifungal treatment

Mucorales can cause cutaneous to deep-seated infections, mainly in the immunocompromised host, resulting in high mortality rates due to late and inefficient treatment. In this study, Galleria mellonella larvae were evaluated as a heterologous invertebrate host to study pathogenicity of clinically relevant mucormycetes (Rhizopus spp., Rhizomucor spp., Lichtheimia spp., Mucor spp.). All tested species were able to infect G. mellonella larvae. Virulence potential was species-specific and correlated to clinical relevance. Survival of infected larvae was dependent on (a) the species (growth speed and spore size), (b) the infection dose, (c) the incubation temperature, (d) oxidative stress tolerance, and (e) iron availability in the growth medium. Moreover, we exploited the G. mellonella system to determine antifungal efficacy of liposomal amphotericin B, posaconazole, isavuconazole, and nystatin-intralipid. Outcome of in vivo treatment was strongly dependent upon the drug applied and the species tested. Nystatin-intralipid exhibited best activity against Mucorales, followed by posaconazole, while limited efficacy was seen for liposomal amphotericin B and isavuconazole. Pharmacokinetic properties of the tested antifungals within this alternative host system partly explain the limited treatment efficacy. In conclusion, G. mellonella represents a useful invertebrate infection model for studying virulence of mucormycetes, while evaluation of treatment response was limited.

Global Epidemiology of Mucormycosis

Mucormycosis is an angio-invasive fungal infection, associated with high morbidity and mortality. A change in the epidemiology of mucormycosis has been observed in recent years with the rise in incidence, new causative agents and susceptible population. The rise has been perceived globally, but it is very high in the Asian continent. Though diabetes mellitus overshadow all other risk factors in Asia, post-tuberculosis and chronic renal failure have emerged as new risk groups. The rhino-cerebral form of mucormycosis is most commonly seen in patients with diabetes mellitus, whereas, pulmonary mucormycosis in patients with haematological malignancy and transplant recipients. In immunocompetent hosts, cutaneous mucormycosis is commonly seen following trauma. The intriguing clinical entity, isolated renal mucormycosis in immunocompetent patients is only reported from China and India. A new clinical entity, indolent mucormycosis in nasal sinuses, is recently recognized. The causative agents of mucormycosis vary across different geographic locations. Though Rhizopusarrhizus is the most common agent isolated worldwide, Apophysomycesvariabilis is predominant in Asia and Lichtheimia species in Europe. The new causative agents, Rhizopus homothallicus, Mucor irregularis, and Thamnostylum lucknowense are reported from Asia. In conclusion, with the change in epidemiology of mucormycosis country-wise studies are warranted to estimate disease burden in different risk groups, analyse the clinical disease pattern and identify the new etiological agents.

Molecular Strategies to Diagnose Mucormycosis

Molecular techniques have provided a new understanding of the epidemiology of mucormycosis and improved the diagnosis and therapeutic management of this life-threatening disease. PCR amplification and sequencing were first applied to better identify isolates that were grown from cultures of biopsies or bronchalveolar lavage samples that were collected in patients with Mucorales infection. Subsequently, molecular techniques were used to identify the fungus directly from the infected tissues or from bronchalveolar lavage, and they helped to accurately identify Mucorales fungi in tissue samples when the cultures were negative. However, these tools require invasive sampling (biospsy, bronchalveolar lavage), which is not feasible in patients in poor condition in Hematology or Intensive Care units. Very recently, PCR-based procedures to detect Mucorales DNA in non-invasive samples, such as plasma or serum, have proved successful in diagnosing mucormycosis early in all patients, whatever the clinical status, and these procedures are becoming essential to improving patient outcome.

A Rare Case of Pulmonary Coinfection by Lichtheimia ramosa and Aspergillus fumigatus in a Patient With Delayed Graft Function After Renal Transplantation

Pulmonary coinfection with Mucor and Aspergillus species has not been reported in organ transplant recipients. Here, we report a rare case of pulmonary coinfection with invasive fungal species in a renal transplant recipient with delayed graft function. The patient was first treated with a regime containing voriconazole, but the infection only worsened. Then, bronchoalveolar lavage fluid culture and internal transcribed spacer region sequencing were performed, and simultaneous pulmonary infection by Lichtheimia ramosa and Aspergillus fumigatus was clearly diagnosed. Susceptibility testing determined that the fungi were sensitive to amphotericin B and posaconazole. Therefore, a therapeutic regime containing posaconazole and amphotericin B liposome, which are less toxic to the kidney, was planned and resulted in resolution of the infectious symptoms. The present case demonstrates the importance of identifying fungal pathogens early and definitively, determining the effective anti-fungal medications, and administering the properly planned therapeutic regime in a timely manner to treat cases of coinfection in transplant recipients.

Disease Entities in Mucormycosis

Mucormycosis is an emerging life-threatening fungal infection caused by Mucorales. This infection occurs mainly in immunocompromised patients, especially with hematological malignancy, transplantation, or diabetes mellitus. Rhino-orbito-cerebral and pulmonary mucormycosis are the predominant forms. Interestingly, location is associated with the underlying disease as pulmonary mucormycosis is more frequent in hematological malignancy patients whereas rhino-orbito-cerebral mucormycosis is associated with diabetes. Cutaneous mucormycosis results from direct inoculation, mainly after trauma or surgery. Gastro-intestinal mucormycosis occurs after ingestion of contaminated food or with contaminated device and involves the stomach or colon. Disseminated disease is the most severe form and is associated with profound immunosuppression. Uncommon presentations with endocarditis, osteoarticluar or isolated cerebral infections are also described. Finally, health-care associated mucormycosis is a matter of concern in premature newborns and burn units. Clinical symptoms and CT scan findings are not specific, only the early reversed halo sign is associated with pulmonary mucormycosis. Circulating Mucorales DNA detection is a recent promising diagnostic tool that may lead to improving the diagnosis and prompting therapeutic initiation that should include antifungal treatment, correction of the underlying disease and surgery when feasible.

Contemporary management and clinical outcomes of mucormycosis: A systematic review and meta-analysis of case reports

With the advent of newer antifungals, optimum treatment of mucormycosis remains to be fully elucidated. This study systematically evaluated the contemporary management and outcomes of mucormycosis. Mucormycosis cases in patients aged ≥18 years published between January 2000 and January 2017 were identified through Ovid MEDLINE and Embase. Of the 3619 articles identified, 600 (851 individual patient cases) were included in the review. Of the 851 patient cases, antifungal treatment details were available for 785. Intravenous (i.v.) amphotericin B formulations remained the most commonly prescribed first-line antifungals (760/785; 96.8%): 88.2% (670/760) were initiated as monotherapy and 11.8% (90/760) as combination antifungal therapy. Posaconazole oral suspension monotherapy was prescribed as an initial antifungal in 11 cases. It was also administered as maintenance or salvage therapy in 39 and 25 cases, respectively. Itraconazole capsule monotherapy (n = 10) was prescribed primarily for cutaneous disease in patients not receiving any immunosuppressive therapy. All-cause 90-day mortality was 41.0% (349/851). Initial treatment with combination antifungals did not reduce 90-day mortality compared with i.v. conventional amphotericin B or i.v. liposomal amphotericin B monotherapy [35/90 (38.9%) vs. 146/369 (39.6%) vs. 91/258 (35.3%), respectively; P = 0.541]. Concomitant surgical and antifungal therapy was associated with significantly lower 90-day mortality compared with treatment with antifungals alone (OR = 0.23, 95% CI 0.13-0.41; P < 0.001). The findings suggest that first-line antifungals with good efficacy remain an urgent unmet need. Whilst surgery is fundamental to improving survival, the clinical utility of combination antifungal therapy or posaconazole monotherapy requires further investigation.

Comparative Analysis of Inflammatory Cytokine Release and Alveolar Epithelial Barrier Invasion in a Transwell® Bilayer Model of Mucormycosis

Understanding the mechanisms of early invasion and epithelial defense in opportunistic mold infections is crucial for the evaluation of diagnostic biomarkers and novel treatment strategies. Recent studies revealed unique characteristics of the immunopathology of mucormycoses. We therefore adapted an alveolar Transwell^® A549/HPAEC bilayer model for the assessment of epithelial barrier integrity and cytokine response to Rhizopus arrhizus, Rhizomucor pusillus, and Cunninghamella bertholletiae. Hyphal penetration of the alveolar barrier was validated by 18S ribosomal DNA detection in the endothelial compartment. Addition of dendritic cells (moDCs) to the alveolar compartment led to reduced fungal invasion and strongly enhanced pro-inflammatory cytokine response, whereas epithelial CCL2 and CCL5 release was reduced. Despite their phenotypic heterogeneity, the studied Mucorales species elicited the release of similar cytokine patterns by epithelial and dendritic cells. There were significantly elevated lactate dehydrogenase concentrations in the alveolar compartment and epithelial barrier permeability for dextran blue of different molecular weights in Mucorales-infected samples compared to Aspergillus fumigatus infection. Addition of monocyte-derived dendritic cells further aggravated LDH release and epithelial barrier permeability, highlighting the influence of the inflammatory response in mucormycosis-associated tissue damage. An important focus of this study was the evaluation of the reproducibility of readout parameters in independent experimental runs. Our results revealed consistently low coefficients of variation for cytokine concentrations and transcriptional levels of cytokine genes and cell integrity markers. As additional means of model validation, we confirmed that our bilayer model captures key principles of Mucorales biology such as accelerated growth in a hyperglycemic or ketoacidotic environment or reduced epithelial barrier invasion upon epithelial growth factor receptor blockade by gefitinib. Our findings indicate that the Transwell^® bilayer model provides a reliable and reproducible tool for assessing host response in mucormycosis.

Successful outcome of disseminated mucormycosis in a 3-year-old child suffering from acute leukaemia: the role of isavuconazole? A case report

BACKGROUND

The use of isavuconazole is approved for the management of invasive aspergillosis and mucormycosis, only in adults, as no paediatric pharmacology studies have been reported to date. Very few paediatric cases have been published concerning the use of isavuconazole. Amphotericin B is the only antifungal agent recommended in paediatric mucormycosis, but adverse effects and especially nephrotoxicity, even with the liposomal formulation, could be problematic. In this context, the use of other antifungal molecules active on Mucorales becomes needful.

CASE PRESENTATION

We describe a case of mucormycosis with rapid onset dissemination in a 3-year-old girl recently diagnosed with acute lymphocytic leukaemia. She was successfully treated with isavuconazole alone and then in combination with liposomal amphotericin B. Isavuconazole therapy was guided by therapeutic drug monitoring.

CONCLUSIONS

This case offers new perspectives on the potential use of isavuconazole in children with mucormycosis, as an alternative or adjunct to liposomal amphotericin B.

[Current therapeutic options in invasive mycosis and potential therapeutic role of isavuconazole]

The treatment of invasive fungal infections has deeply evolved in recent years with the inclusion of new antifungals to the therapeutic treatment arsenal. A new azole, isavuconazole, has been recently approved. This review focuses on the role of isavuconazole for treating the most important invasive fungal infections: invasive candidiasis, aspergillosis, mucormicosis, infections caused by other filamentous fungi and those caused by dimorphic fungi.

Invasive mucormycosis in children with cancer: A retrospective study from the Infection Working Group of Italian Pediatric Hematology Oncology Association

BACKGROUND

Invasive mucormycosis is a rare but frequently fatal fungal disease. The acute and rapidly progressive evolution causes unfavourable outcome in 22%-59% of patients and its treatment represents a clinical challenge, especially in immunocompromised patients. Current data in paediatric oncological patients are limited.

OBJECTIVES

The infection Working Group of the Italian Association of Pediatric Hematology and Oncology (AIEOP) analysed the episodes of invasive mucormycosis occurred between 2009 and 2016.

PATIENTS

Fifteen cases of proven mucormycosis (male/female 8/7; median age 14.1 years, range 7.7-18.6) were reported after chemotherapy for acute leukaemia and lymphoma (12) and allogeneic stem cell transplantation (3). The aetiology was Rhizopus oryzae 4, Lichtheimia corymbifera 3 and Mucor spp. 8.

RESULTS

Paranasal sinus was the primary site of infection in 14/15 patients combined with orbital involvement (9), central nervous system (8), lung (4), thyroid gland and kidney (1). All patients received liposomal Amphotericin B (L-AmB) (3-10 mg/kg), with surgical debridement in 14/15 cases. Eleven patients received maintenance treatment with posaconazole (9) or isavuconazole (2). Eight out of fifteen patients (53.3%) died, after 3-6 months.

CONCLUSIONS

Mucormycosis involved mainly the sinu-orbital site and affected children >10 years. Despite aggressive treatment with high-dose L-AmB and timely surgical debridement, the mortality rate remains still high.

Diagnosis and Treatment of Isolated Cerebral Mucormycosis: Patient-Level Data Meta-Analysis and Mayo Clinic Experience

BACKGROUND

Isolated cerebral mucormycosis is a rare and serious infection associated with intravenous drug abuse.

METHODS

We performed a comprehensive meta-analysis of cases reported in studies and have included an unreported case from our institution. We searched PubMed/Medline, EMBASE, Scopus, Cochrane Databases, and our institution's electronic medical health records from inception through March 31, 2018. The cases were considered isolated (only affecting the cerebrum, cerebellum, or brainstem) if the absence of other primary sources of infection had been documented. Continuous variables were summarized using the median and interquartile range and categorical variables using frequencies and proportions. The relationships between variables were tested using the Wilcoxon rank sum and Pearson χ² tests.

RESULTS

A total of 130 studies (141 patients) met the eligibility requirements and were screened; 68 patients were included. The median age was 28 years (interquartile range, 24-38); 57% were men. Most patients had a history of intravenous drug abuse (82%), and 20% had positive human immunodeficiency virus findings. The lesion location was mostly supratentorial (91%), especially in the basal ganglia (71.2%). The cultures were positive in 38%, with Rhizopus the most common organism (59%). The mortality rate was 65%. The survivors were significantly more likely to have received amphotericin B (92% vs. 43%; P < 0.001) or to have undergone stereotactic aspiration (58% vs. 25%; P < 0.01).

CONCLUSIONS

Isolated cerebral mucormycosis has a pooled mortality rate of 65%. The presence of lesions in the basal ganglia, rapidly progressive symptoms, and a history of intravenous drug abuse should raise suspicion for the early initiation of amphotericin B and stereotactic aspiration.

Successful treatment of pulmonary mucormycosis in two pediatric hematopoietic stem cell transplant patients

Pulmonary mucormycosis diagnosed immediately after hematopoietic stem cell transplantation frequently portends a poor prognosis. However, here we describe two cases in children that were treated successfully to highlight the efficacy of a multidisciplinary approach. Despite diagnosis in the immediate post-transplant period and requirement for ongoing immunosuppression to prevent or treat GVHD, both are long-term survivors due to early surgical debridement with transfusion support and prompt initiation of targeted antifungal therapy. In the absence of evidence-based treatment guidelines, survival of pulmonary mucormycosis is achievable even in high-risk patients with a multidisciplinary team to guide management.

Recent advances in the understanding and management of mucormycosis

Mucormycoses were difficult-to-manage infections owing to limited diagnostic tools and therapeutic options. We review here advances in pathology understanding, diagnostic tools including computed tomography, and serum polymerase chain reaction and therapeutic options.

Successful Treatment of Intestinal Mycosis Caused by a Simultaneous Infection with Lichtheimia ramosa and Aspergillus calidoustus

A 53-year-old woman was hospitalized due to septic shock after developing pneumococcal pneumonia after undergoing esophageal cancer surgery. Her transverse colon became perforated after receiving antimicrobial chemotherapy; therefore, emergency subtotal colectomy was performed. Fungi detected in both her colon tissue and a drainage sample indicated intestinal mucormycosis. Early intensive treatment with high-dose liposomal amphotericin B was successful, and she was subsequently discharged from the hospital. The fungal isolates were identified to be Lichtheimia ramosa and Aspergillus calidoustus via gene sequencing using panfungal primers as well as species-specific primers against elongation factor 1 and beta-tubulin for detecting Lichtheimia and Aspergillus, respectively.

Invasive hepatic mucormycosis: A case report and review of the literature

Mucormycosis generally develops under immunocompromised conditions, including hematological malignancies and solid organ or hematopoietic stem cell transplantation. Although mucormycosis usually affects the lungs and paranasal sinuses, sporadic cases of invasive mucormycosis of the liver have been reported. We hereby report a patient with myelofibrosis who developed hepatic mucormycosis diagnosed by post-mortem examination. An extensive literature review identified 13 reported cases of hepatic mucormycosis, including ours, without lung involvement. Most of the underlying diseases or conditions were hematological malignancies and solid organ transplantation. Three cases had splenic lesions and four had gastrointestinal lesions, suggesting the possibility of translocation to the liver and/or spleen from the gastrointestinal tracts. Hepatic mucormycosis should be recognized as one of the presentations of invasive mucormycosis, especially when hepatic nodules are found in immunocompromised patients such as those with hematological malignancy or recipients of solid organ transplantation.

Quantitative PCR (qPCR) Detection of Mucorales DNA in Bronchoalveolar Lavage Fluid To Diagnose Pulmonary Mucormycosis

Early diagnosis and treatment are essential to improving the outcome of mucormycosis. The aim of this retrospective study was to assess the contribution of quantitative PCR detection of Mucorales DNA in bronchoalveolar lavage fluids for early diagnosis of pulmonary mucormycosis. Bronchoalveolar lavage fluid samples (n = 450) from 374 patients with pneumonia and immunosuppressive conditions were analyzed using a combination of 3 quantitative PCR assays targeting the main genera involved in mucormycosis in France (Rhizomucor, Mucor/Rhizopus, and Lichtheimia). Among these 374 patients, 24 patients had at least one bronchoalveolar lavage fluid sample with a positive PCR; 23/24 patients had radiological criteria for invasive fungal infections according to consensual criteria; 10 patients had probable or proven mucormycosis, and 13 additional patients had other invasive fungal infections (4 probable aspergillosis, 1 proven fusariosis, and 8 possible invasive fungal infections). Only 2/24 patients with a positive PCR result on a bronchoalveolar lavage fluid sample had a positive Mucorales culture. PCR was also positive on serum in 17/24 patients. In most cases, a positive PCR result was first detected using sera (15/17). However, a positive PCR on bronchoalveolar lavage fluid was the earliest and/or the only biological test revealing mucormycosis in 4 patients with a final diagnosis of probable or proven mucormycosis, 3 patients with probable aspergillosis, and one patient with a possible invasive fungal infection. Mucorales PCR performed on bronchoalveolar lavage fluid could provide additional support for earlier administration of Mucorales-directed antifungal therapy, thus improving the outcome of lung mucormycosis cases.

Rhinocerebral mucormycosis, risk factors and the type of oral manifestations in patients referred to a University Hospital in Tabriz, Iran 2007-2017

Inadequate data are available on the global epidemiology of mucormycosis, mainly derived from the evaluation of specific population groups. Rhinocerebral mucormycosis is an invading and fatal mycosis, particularly among diabetic patients. In the present study, patients hospitalised in Imam Reza Hospital in Tabriz, from 2007 to 2017, were evaluated. The hospital information system (HIS) was used to collect the records of the patients. A total of 42 patients with a diagnosis of mucormycosis were included in the study, 40 cases (95%) of which had a diagnosis of the rhinocerebral form. Of these 40 patients, 21 (52.5%) and 19 (47.5%) were male and female, respectively. Seven cases (17.5%) of rhinocerebral mucormycosis were due to dental procedures. The most predisposing factor in the patients was diabetes with 36 (90%) cases. In our study, the role of tooth extraction in patients with uncontrolled diabetes was identified as an important factor. It may show the important role of dentists in preventing of the disease in diabetic patients.

Genetic tools for investigating Mucorales fungal pathogenesis

Purpose of review

Mucormycosis is an emerging opportunistic fungal infection whose causative agents are found within the Mucorales family. A recent increase in immunocompromised cohorts with solid organ transplants, diabetes mellitus, and other medical conditions have resulted in increased fungal infections including mucormycosis. Our current knowledge about Mucoralean fungi is in its infancy compared to other fungal pathogens, which may be due to lack of robust genetic tools for Mucorales. In this review we summarize recent advances in genetic tools to study the two most prevalent and genetically amenable Mucoralean fungi, Mucor circinelloides and Rhizopus delemar.

Recent findings

There have been advances made in the study of Mucorales family genetics. These findings include the construction of recyclable markers to manipulate the genome, as well as silencing vectors, and the adaptation of the CRISPR/Cas9 gene editing system.

Summary

We present how these genetic methods have been applied to understand basic biology, morphogenesis, pathogenesis, and host-pathogen interactions in the two Mucoralean fungi, M. circinelloides and R. delemar. With these advances in Mucorales the opportunity to further understand the pathogenesis of these organisms is opened.

Cutaneous Mucormycosis Following a Bullous Pemphigoid Flare in a Chronic Lymphocytic Leukemia Patient on Ibrutinib

While the recent development of novel therapeutics in oncology, such as small molecule kinase inhibitors (SMKIs), has enabled our ability to target disease-specific molecular pathways, the prolonged impact of these agents on the immune system and infectious risk remains to be seen. We present a 68-year-old male with refractory chronic lymphocytic leukemia (CLL) on ibrutinib monotherapy for 3 years who developed extensive cutaneous mucormycosis following a severe bullous pemphigoid (BP) flare. He received amphotericin B for 4 weeks and was continued on posaconazole with resolution of his mucormycosis infection. Consistent with a growing evidence of literature identifying opportunistic fungal infections in patients on ibrutinib therapy, providers should be cognizant of medical comorbidities that may predispose to such infections and explore methods of prevention before starting ibrutinib and other SMKIs.

Outbreak of Invasive Wound Mucormycosis in a Burn Unit Due to Multiple Strains of Mucor circinelloides f. circinelloides Resolved by Whole-Genome Sequencing

Mucorales are ubiquitous environmental molds responsible for mucormycosis in diabetic, immunocompromised, and severely burned patients. Small outbreaks of invasive wound mucormycosis (IWM) have already been reported in burn units without extensive microbiological investigations. We faced an outbreak of IWM in our center and investigated the clinical isolates with whole-genome sequencing (WGS) analysis. We analyzed M. circinelloides isolates from patients in our burn unit (BU1, Hôpital Saint-Louis, Paris, France) together with nonoutbreak isolates from Burn Unit 2 (BU2, Paris area) and from France over a 2-year period (2013 to 2015). A total of 21 isolates, including 14 isolates from six BU1 patients, were analyzed by whole-genome sequencing (WGS). Phylogenetic classification based on de novo assembly and assembly free approaches showed that the clinical isolates clustered in four highly divergent clades. Clade 1 contained at least one of the strains from the six epidemiologically linked BU1 patients. The clinical isolates were specific to each patient. Two patients were infected with more than two strains from different clades, suggesting that an environmental reservoir of clonally unrelated isolates was the source of contamination. Only two patients from BU1 shared one strain, which could correspond to direct transmission or contamination with the same environmental source. In conclusion, WGS of several isolates per patients coupled with precise epidemiological data revealed a complex situation combining potential cross-transmission between patients and multiple contaminations with a heterogeneous pool of strains from a cryptic environmental reservoir.

Invasive wound mucormycosis (IWM) is a severe infection due to environmental molds belonging to the order Mucorales. Severely burned patients are particularly at risk for IWM. Here, we used whole-genome sequencing (WGS) analysis to resolve an outbreak of IWM due to Mucor circinelloides that occurred in our hospital (BU1). We sequenced 21 clinical isolates, including 14 from BU1 and 7 unrelated isolates, and compared them to the reference genome (1006PhL). This analysis revealed that the outbreak was mainly due to multiple strains that seemed patient specific, suggesting that the patients were more likely infected from a pool of diverse strains from the environment rather than from direct transmission among them. This study revealed the complexity of a Mucorales outbreak in the settings of IWM in burn patients, which has been highlighted based on WGS combined with careful sampling.

Gastric Mucormycosis in a Liver and Kidney Transplant Recipient: Case Report and Concise Review of Literature

Mucormycosis is an uncommonly encountered fungal infection in solid organ transplantation. The infection is severe and often results in a fatal outcome. The most common presentations are rhino-sino-orbital and pulmonary disease. We describe a rare case of gastric mucormycosis in a patient with a combined liver-kidney transplant affected by glycogen storage disease type Ia. A 42-year-old female patient presented with gastric pain and melena 26 days after transplantation. Evaluation with upper endoscopy showed two bleeding gastric ulcers. Histological examination of gastric specimens revealed fungal hyphae with evidence of Mucormycetes at subsequent molecular analysis. Immunosuppressive therapy was reduced and antifungal therapy consisting of liposomal amphotericin B and posaconazole was promptly introduced. Gastrointestinal side effects of posaconazole and acute T-cell rejection of renal graft complicated management of the case. A prolonged course of daily injections of amphotericin B together with a slight increase of immunosuppression favored successful treatment of mucormycosis as well as of graft rejection. At 2-year follow-up, the woman was found to have maintained normal renal and liver function. We conclude that judicious personalization of antimicrobial and antirejection therapy should be considered to resolve every life-threatening case of mucormycosis in solid organ transplantation.

Mucormycosis in Iran: A six-year retrospective experience

Mucormycosis is a devastating infection caused by Mucoralean fungi (Mucormycotina, Mucorales). Data concerning the global epidemiology of mucormycosis are scarce and little is known about the characteristics of mucormycosis in Iran. In this study, we aimed to understand the distribution of this infection in Iran retrospectively and to ascertain whether the patterns of infection are associated with specific host factors or not. A total of 208 cases were included in this study occurring during 2008-2014 and were validated according to (EORTC/MSG) criteria. A rising trend as significant increase from 9.7% in 2008 to 23.7% in 2014 was observed. The majority of patients were female (51.4%) with median age of 50 and the infections were seen mostly in autumn season (39.4%). Diabetes mellitus (75.4%) was the most common underlying condition and sinus involvement (86%) was the mostly affected site of infection. Amphotericin B (AmB) was the drug of choice for the majority of cases. Sixty four isolates did not show any growth in the lab and only 21 cases were evaluated by ITS sequencing, among them; Rhizopus arrhizus var. arrhizus was the dominant species. Considering the high mortality rate of mucormycosis, early and accurate diagnosis, with the aid of molecular methods may provide accurate treatments and improve the survival rate. Therefore, increased monitoring and awareness of this life-threatening disease is critical.

New insights into the clinical characteristics and prognostic factors of pulmonary fungal infections from a retrospective study in Southwestern China

Background

Despite increasing incidence of pulmonary fungal infections (PFIs) worldwide, the clinical characteristics and prognostic factors remain poorly understood. The goal of this study was to investigate the clinical features, laboratory findings, and outcomes of hospitalized patients diagnosed with PFIs.

Methods

We retrospectively enrolled 123 patients at a university hospital in Southwestern China between February 2014 and May 2016, who were diagnosed with PFIs based on clinical presentations and laboratory tests including fungal culture and pathological examination. Medical records were reviewed and analyzed. Prognostic factor associated with mortality was evaluated by multivariate regression analysis.

Results

Of the 123 PFI patients enrolled, the mean age was 67 years with 72% of them being males. In addition to common clinical features reported previously, these patients exhibited distinct characteristics, with the elderly accounting for 79% of all cases, and with prolonged hospitalization being the most prevalent risk factor (74%) and chronic obstructive pulmonary disease (COPD) being the most common underlying disease (45%). Invasive operation was significantly more frequently involved in patients with unfavorable treatment responses than in patients with favorable responses (45.6 vs 7.4%, P=0.000). By multivariate regression analysis, invasive operation (odds ratio [OR]: 5.736, 95% confidence interval [CI]: 2.008–16.389, P=0.001) and hypoalbuminemia (OR: 3.936, 95% CI: 1.325–11.696, P=0.014) were independent prognostic factors of mortality in PFIs.

Conclusion

This study provides new insights into the clinical characteristics and prognostic factors of PFIs and highlights the necessity to be aware of PFIs in patients with COPD and patients receiving invasive operation in order to improve clinical management of these patients.

Severe dermatophytosis in solid organ transplant recipients: A French retrospective series and literature review

OBJECTIVE

Severe dermatophytosis is described in immunocompromised patients with defective cellular immunity. We report here a large series and a literature review of severe dermatophytosis in solid-organ transplant (SOT) recipients.

METHOD

The data main source was a national French retrospective study of severe dermatophytosis in SOT recipients between 2010 and 2016. Inclusion criteria were the presence of dermatophytes in skin culture and 1 severity criteria: dermal invasion by dermatophytes (invasive dermatophytosis) or involvement of at least two body sites or >10% of body surface area (extensive dermatophytosis).

RESULTS

A total of 12 patients were included (8 men, median age of 56 years [range: 33-71]). Of the 12 patients, 10 underwent kidney transplantation. The median time from transplantation to severe dermatophytosis diagnosis was 16 months [range: 2-94]. Clinical signs of superficial dermatophytosis were present in 8/12 patients before the emergence of severe dermatophytosis. Nine patients had invasive forms and three extensive ones, and nodules of the lower extremities were found in eight. Trichophyton rubrum was isolated in 11 cases. First-line treatment was terbinafine (7/12), posaconazole (3/12), or topical treatment alone (2/12). Immunosuppressive therapy was reduced in 3 patients because of associated infections. Complete response was obtained for 3/3 and 5/9 patients with extensive or invasive forms, respectively, after a median treatment's duration of 2.5 [range: 1.5-5] months and 7.5 months [range: 4-12]. Unrelated deaths (n = 2) and graft function impairment (n = 3) occurred.

CONCLUSION

Severe dermatophytosis is a late complication in SOT recipients presenting with lower limb nodules, which might be prevented by prompt treatment of superficial dermatophytosis.

Assessment of occupational exposure to azole resistant fungi in 10 Portuguese bakeries

Occupational exposure to bioaerosols resulting from handling of flour dust and raw materials in bakeries is associated with health problems. The emergence of azole-resistant fungal species in the environment is thought to be related with the use of azole fungicides in cereal crops and prevention of postharvest spoilage. As raw materials used in bakeries are commonly exposed to azoles, we investigated the mycobiota and azole-resistant fungi prevalence in this occupational environment. Ten Portuguese bakeries were assessed through electrostatic dust cloth (EDC, n = 27), settled dust (n = 7), and raw material (n = 26) samples. Samples were inoculated in malt extract agar (2%) (MEA) with chloramphenicol (0.05 g/L) and in dichloran glycerol (DG18), and onto Saboraud screening media supplemented with 4 mg/L itraconazole, 1 mg/L voriconazole, or 0.5 mg/L posaconazole, and incubated for 3–5 days at 27 °C. Except for one out of the ten analyzed bakeries, Cladosporium sp., Penicillium sp., and Aspergillus sp. were the most prevalent fungi identified. Aspergillus sp. and Mucorales order were identified in raw materials with both media, whereas Penicillium sp. was identified in DG18 only. Azole-resistant species were identified in the environment (EDC) and, to a lower extent, in raw materials, including Aspergillus sp. and Mucorales. The presence of azole-resistant fungal species in bakeries represents an occupational risk for workers. This study proposes complementary sampling methods for the evaluation of occupational exposure to mycobiota, and highlights the importance of studying the prevalence of azole-resistant strains in specific occupational environments.

Higher In vitro Proliferation Rate of Rhizopus oryzae in Blood of Diabetic Individuals in Chronic Glycaemic Control Compared with Non-diabetic Individuals

Metabolic control improves outcomes associated with mucormycosis. The aim of this study was to compare the in vitro proliferation of Rhizopus oryzae in blood of individuals with and without diabetes at different glycaemic levels. Ninety-five individuals were included. Blood samples from each participant were incubated with sporangiospores of R. oryzae. The germination, filamentation and growth of R. oryzae were compared at different time points. Four groups were defined, one without (group A, n = 30) and three with diabetes: group B (HbA1c ≤7%, N = 24), group C (HbA1c 7.1-9%, N = 20) and group D (HbA1c > 9%, N = 21). The percentage of germinated sporangiospores was higher in the group A after 6 h (group A 56% ± 3, group B 35% ± 4, group C 48% ± 4, group D 46% ± 1.4, p = 0.01), 12 h (group A 54% ± 1.4, group B 19% ± 4, group C 16% ± 1, group D 9.5% ± 5, p < 0.001) and 24 h (group A 29% ± 1, group B 12% ± 4, group C 13.5% ± 3.5, group D 12% ± 1, p < 0.01). The filamentation was higher in groups with diabetes. Group B showed higher filamentation grade than group A at 6 h (0.4 ± 0.04 vs 1 ± 0.09, p < 0.001) and 24 h (1.6 ± 0.05 vs 2.1 ± 0.1, p = 0.05). In conclusion, R. oryzae proliferation was higher among diabetic individuals, including good glycaemic control, than among non-diabetic individuals.

Diagnosis and Treatment of Mucormycosis in Patients withHematological Malignancies［Translated Article］

The risk of invasive fungal infections (IFIs) is extremely high in patients with hematological malignancies due to the prolonged and profound neutropenia and immunosuppression after chemotherapy and hematopoietic stem cell transplantation. There has been increasing interest in mucormycosis despite its relatively uncommon occurrence, because occasional breakthrough infections have been observed under anti-Aspergillus prophylaxis. The aggressive nature of mucormycosis easily leads to high mortality because of delays in diagnosis and incorrect treatment decisions, which are due in part to lack of adjunctive diagnostic tools and having similar clinical and radiological features with invasive aspergillosis. The only currently available antifungals against Mucorales in Japan are amphotericin B formulations. Thus, comprehensive therapeutic strategies, including surgery, should be considered to achieve a successful outcome.

Prophylactic Treatment with VT-1161 Protects Immunosuppressed Mice from Rhizopus arrhizus var. arrhizus Infection

We compared prophylactic or continuous therapy with the investigational drug VT-1161 to that with posaconazole in treating murine mucormycosis due to Rhizopus arrhizus var. arrhizus In the prophylaxis studies, only VT-1161 resulted in improved survival and lowered tissue fungal burden of immunosuppressed infected mice. In the continuous therapy, VT-1161 outperformed posaconazole in prolonging mouse survival time despite its comparable effect in lowering tissue fungal burden. These results support the further development of VT-1161 against mucormycosis.

Ketoacidosis alone does not predispose to mucormycosis by Lichtheimia in a murine pulmonary infection model

Mucormycosis is a rare fungal infection; however, the number of cases increased during the last decades. The main risk factors are immunosuppression and uncontrolled diabetes mellitus. Although Lichtheimia species represent a common cause of mucormycosis in Europe, virulence and pathogenesis of this genus has not been investigated in detail yet. Using murine pulmonary infection models, we found that immunosuppression is essential for establishment of infection. The disease was characterized by necrosis, angioinvasion, thrombosis, and the lethal course of infection was associated with systemic activation of platelets. Furthermore, dissemination to internal organs was frequently observed. While the virulence potential of individual L. corymbifera and L. ramosa isolates differed, pathogenicity of both species was comparable. Although ketoacidosis promoted Rhizopus infection in mice, it did not predispose mice to infection with Lichtheimia in the absence of additional immunosuppression. This might partially explain the dominance of Rhizopus as cause of mucormycosis in countries with high prevalence of ketoacidotic patients.

Antifungal resistance in mucorales

The order Mucorales, which includes the agents of mucormycosis, comprises a large number of species. These fungi are characterised by high-level resistance to most currently available antifungal drugs. Standardised antifungal susceptibility testing methods are now available, allowing a better understanding of the in vitro activity of antifungal drugs against members of Mucorales. Such tests have made apparent that antifungal susceptibility within this group may be species-specific. Experimental animal models of mucormycosis have also been developed and are of great importance in bridging the gap between in vitro results and clinical trials. Amphotericin B, posaconazole and isavuconazole are currently the most active agents against Mucorales; however, their activity remains suboptimal and new therapeutic strategies are needed. Combination therapy could be a promising approach to overcome resistance, but further studies are required to confirm its benefits and safety for patients.

Mucorales spores induce a proinflammatory cytokine response in human mononuclear phagocytes and harbor no rodlet hydrophobins

Mucormycoses are life-threatening infections in immunocompromised patients. This study characterizes the response of human mononuclear cells to different Mucorales and Ascomycota. PBMC, monocytes, and monocyte derived dendritic cells (moDCs) from healthy donors were stimulated with resting and germinated stages of Mucorales and Ascomycota. Cytokine response and expression of activation markers were studied. Both inactivated germ tubes and resting spores of Rhizopus arrhizus and other human pathogenic Mucorales species significantly stimulated mRNA synthesis and secretion of proinflammatory cytokines. Moreover, R. arrhizus spores induced the upregulation of co-stimulatory molecules on moDCs and a specific T-helper cell response. Removal of rodlet hydrophobins by hydrofluoric acid treatment of A. fumigatus conidia resulted in enhanced immunogenicity, whereas the cytokine response of PBMCs to dormant R. arrhizus spores was not influenced by hydrofluoric acid. Scanning electron micrographs of Mucorales spores did not exhibit any morphological correlates of rodlet hydrophobins. Taken together, this study revealed striking differences in the response of human mononuclear cells to resting stages of Ascomycota and Mucorales, which may be explained by absence of an immunoprotective hydrophobin layer in Mucorales spores.

Invasive Fungal Infections Secondary to Traumatic Injury

Invasive fungal infection (IFI) is a rare but serious complication of traumatic injury. The purpose of this article is to review the epidemiology, natural history, mycology, risk factors, diagnosis, treatment, and outcomes associated with post-traumatic IFI in military and civilian populations. The epidemiology of post-traumatic IFI is poorly characterized, but incidence appears to be rising. Patients often suffer from severe injuries and require extensive medical interventions. Fungi belonging to the order Mucorales are responsible for most post-traumatic IFI in both civilian and military populations. Risk factors differ between these cohorts but include specific injury patterns and comorbidities. Diagnosis of post-traumatic IFI typically follows positive laboratory results in the appropriate clinical context. The gold standard of treatment is surgical debridement in addition to systemic antifungal therapy. Patients with post-traumatic IFI may be at greater risk of amputation, delays in wound healing, hospital complications, and death as compared to trauma patients who do not develop IFI. More research is needed to understand the factors surrounding the development and management of post-traumatic IFI to reduce the significant morbidity and mortality associated with this disease.

The current treatment landscape: other fungal diseases (cryptococcosis, fusariosis and mucormycosis)

Compared with major invasive mycoses such as aspergillosis and candidiasis, the antifungal stewardship management strategies of other fungal diseases have different opportunities and considerations. Cryptococcosis, fusariosis and mucormycosis are globally prevalent invasive fungal diseases (IFDs), but are not currently included in antifungal prophylaxis guidelines for immunocompromised hosts. Since the implementation of biomarkers as part of diagnostic screening strategies, the concept of pre-emptive antifungal therapy has emerged for these IFDs. Management of cryptococcosis, the most common IFD worldwide, generally utilizes a pre-emptive or therapeutic strategy that does not involve prophylaxis or empirical antifungal treatment strategies. Antifungal stewardship outcomes for cryptococcosis may vary according to the availability of local resources. Invasive fusariosis, the second-most common form of non-Aspergillus mould infection among haematological malignancy patients, can be managed with pre-emptive (or diagnostic-driven) approaches based on the monitoring of serum galactomannan (GM) antigen in increased-risk populations. The success of antimicrobial stewardship programmes in decreasing the burden of invasive fusariosis in selected patient populations depends on the development and implementation of rapid diagnostic strategies for early and appropriate administration of therapy. Mucormycosis may emerge as a breakthrough IFD in haematology or solid organ transplant recipients receiving antifungals that lack activity against Mucorales. The concept of pre-emptive antifungal therapy has thus arisen for mucormycosis in the haematology setting because of the recent availability of circulating Mucorales DNA measurement. These examples demonstrate the challenges of implementing antifungal stewardship programmes in areas with limited resources, as well as in IFDs that are difficult to diagnose and treat.

[Fungal sinusitis]

Although sinusitis affects about 20 % of the population, fungal sinusitis is rare. Aspergillus sp. are most frequently implicated. Fungal sinusitis represents a wide spectrum of disorders, including acute or chronic and invasive or non-invasive forms. Invasive fungal sinusitis may develop in an immunocompromised or diabetic patient, whereas non-invasive fungal sinusitis should be considered in a chronic situation, resistant to antibiotics in immunocompetent patients. Allergic fungal sinusitis is related to hypersensitivity of the host to the fungus. The diagnosis of these infections requires radiological examination and endoscopy with mucosal biopsies examined histologically and mycologically in order to distinguish the different types of sinusitis. In the non-invasive forms, surgical treatment is essential, sometimes combined with antifungal and anti-inflammatory treatment. The invasive forms require antifungal treatment, combined with surgery in some forms, particularly mucormycosis.

Invasive mould infections in the ICU setting: complexities and solutions

Infections caused by filamentous fungi represent a major burden in the ICU. Invasive aspergillosis is emerging in non-neutropenic individuals with predisposing conditions, e.g. corticosteroid treatment, chronic obstructive pulmonary disease, liver cirrhosis, solid organ cancer, HIV infection and transplantation. Diagnosis is challenging because the signs and symptoms are non-specific, and initiation of additional diagnostic examinations is often delayed because clinical suspicion is low. Isolation of an Aspergillus species from the respiratory tract in critically ill patients, and tests such as serum galactomannan, bronchoalveolar lavage 1-3-β-d-glucan and specific PCR should be interpreted with caution. ICU patients should start adequate antifungal therapy upon suspicion of invasive aspergillosis, without awaiting definitive proof. Voriconazole, and now isavuconazole, are the drugs of choice. Mucormycosis is a rare, but increasingly prevalent disease that occurs mainly in patients with uncontrolled diabetes mellitus, immunocompromised individuals or previously healthy patients with open wounds contaminated with Mucorales. A high proportion of cases are diagnosed in the ICU. Rapidly progressing necrotizing lesions in the rhino-sinusal area, the lungs or skin and soft tissues are the characteristic presentation. Confirmation of diagnosis is based on demonstration of tissue invasion by non-septate hyphae, and by new promising molecular techniques. Control of underlying predisposing conditions, rapid surgical resection and administration of liposomal amphotericin B are the main therapeutic actions, but new agents such as isavuconazole are a promising alternative. Patients with mucormycosis receive a substantial part of their care in ICUs and, despite advances in diagnosis and treatment, mortality remains very high.

[Complications of sinusitis]

The complications of sinusitis are essentially secondary to ethmoidal and frontal sinusitis, occurring in patients weakened, particularly in case of immunodeficiency or anatomical defects. The gravity is due to the risk of spreading infection in intracranial tissues and orbital cavity. The diagnosis is always to discuss any symptomatology resistant to treatment and the appearance of orbital or neurological signs. The scanner and MRI contribute greatly to the orientation and diagnostic evaluation of the extent of the lesions. Treatment is based on prolonged antibiotic therapy and surgery and requires a multidisciplinary approach involving ENT, ophthalmologist, neurosurgeon and anesthesiologist resuscitator.

Construction of a Recyclable Genetic Marker and Serial Gene Deletions in the Human Pathogenic Mucorales Mucor circinelloides

Mucor circinelloides is a human pathogen, biofuel producer, and model system that belongs to a basal fungal lineage; however, the genetics of this fungus are limited. In contrast to ascomycetes and basidiomycetes, basal fungal lineages have been understudied. This may be caused by a lack of attention given to these fungi, as well as limited tools for genetic analysis. Nonetheless, the importance of these fungi as pathogens and model systems has increased. M. circinelloides is one of a few genetically tractable organisms in the basal fungi, but it is far from a robust genetic system when compared to model fungi in the subkingdom Dikarya. One problem is the organism is resistant to drugs utilized to select for dominant markers in other fungal transformation systems. Thus, we developed a blaster recyclable marker system by using the pyrG gene (encoding an orotidine-5'-phosphate decarboxylase, ortholog of URA3 in Saccharomyces cerevisiae). A 237-bp fragment downstream of the pyrG gene was tandemly incorporated into the upstream region of the gene, resulting in construction of a pyrG-dpl237 marker. To test the functionality of the pyrG-dpl237 marker, we disrupted the carRP gene that is involved in carotenoid synthesis in pyrG^- mutant background. The resulting carRP::pyrG-dpl237 mutants exhibit a white colony phenotype due to lack of carotene, whereas wild type displays yellowish colonies. The pyrG marker was then successfully excised, generating carRP-dpl237 on 5-FOA medium. The mutants became auxotrophic and required uridine for growth. We then disrupted the calcineurin B regulatory subunit cnbR gene in the carRP::dpl237 strain, generating mutants with the alleles carRP::dpl237 and cnbR::pyrG These results demonstrate that the recyclable marker system is fully functional, and therefore the pyrG-dpl237 marker can be used for sequential gene deletions in M. circinelloides.

Increasing incidence of mucormycosis in a large Spanish hospital from 2007 to 2015: Epidemiology and microbiological characterization of the isolates

We studied 19 cases of proven/probable mucormycosis diagnosed from 2007 to 2015 in our hospital and assessed the microbiological characteristics of the isolates. We recorded the incidence of mucormycosis and clinical and microbiological data of infected patients. Isolates were identified to molecular level and tested for their antifungal susceptibility to azoles, amphotericin B, and liposomal amphotericin B according to the CLSI M-38 A2 procedure. The incidence of mucormycosis in cases/100,000 hospital admissions during 2007–2015 increased significantly with respect to that reported in 1988–2006 (3.3 vs. 1.2; P<0.05). Patients mainly had hematological malignancies (52.6%) and/or trauma/surgical wounds (52.6%) and had received antifungal agents before the diagnosis of mucormycosis in 68% of cases. Diagnosis was by isolation (n = 17/19) and/or direct staining (n = 17/18) of Mucorales fungi in clinical samples. Identification was by panfungal PCR in patients with negative results in culture and in direct staining. The microorganisms identified were Lichtheimia spp. (42%), Rhizopus spp. (21%), Cunninghamella bertholletiae (16%), and others (21%). Liposomal amphotericin B was always more active than the other drugs against all the microorganisms except C. bertholletiae. All patients received antifungal treatment with 1 or more antifungal agents, mainly liposomal amphotericin B (17/19). Mortality was 47.4%, although this was significantly lower in the 11 patients in whom debridement was performed (18% vs. 87.5%) (P = 0.015). The incidence of mucormycosis has risen in recent years. The proportion of cases with soft tissue involvement was high, and Lichtheimia was the most frequently involved species. The highest antifungal activity was observed with liposomal amphotericin B.